The present invention generally relates to apparatus and methods for recovering fumes, particularly to apparatus and methods for recovering fumes during the application of a heated, waterproofing material to a roof, and specifically to apparatus and methods for recovering and burning fumes from a heated, waterproofing material.
During the installation of many flat roofs, waterproofing material is heated such as in a roofing kettle or like tanker and pumped therefrom onto a roof. To avoid pressure build-up as the result of heating the material and to prevent the creation of a vacuum during pumping, the kettle is vented to the atmosphere. Unfortunately, such venting also allows the escape of fumes to the atmosphere, which fumes are extremely repugnant to many. In fact, many roofing contracts, especially for schools, hospitals, residential areas and the like, require that the fumes from at least the roofing kettle be recovered and not be allowed to escape to the atmosphere.
Prior attempts to solve this problem in the field of roofing material application included the use of filtration units such as disclosed in U.S. Pat. No. 5,591,244. Such units are undesirable for several reasons. First, such filter units require a large initial capital investment. Further, operation of such units causes the filters thereof to become plugged requiring replacement. In addition to the cost of the filters and their installation, disposal costs can be large as often such plugged filters are classified as hazardous waste. Additionally, air is required to be drawn through the filters even as material filtered from the air collects on the filter. Thus, large fans are required, which require considerable energy input and are quite noisy. Also, considerable heat is withdrawn from the kettle with the air and thereby increasing the amount of heat which must be supplied to the material by the kettle. Additionally, such filter units are quite large and often are required to be transported to the job site by a flat bed truck.
Another attempt to solve this problem has been the use of an afterburner such as manufactured by Reeves Roofing Equipment Co., Inc. of Helotes, Tex. 78023. Generally, such an afterburner includes a vertical chimney upstanding from a roofing kettle lid or cover. A burner was positioned in the chimney. The heat from the burner causes air to rise in the chimney and be drawn from the interior of the roofing kettle. The fumes passing through the chimney and past the burner are burned to eliminate visible smoke and odor. Although fire screens are provided, fire and explosions are of concern because the burner in the afterburner is in close proximity to the material in the roofing kettle and there is no provision for stopping gas flow to the burner in the afterburner in the event that the burner flame does not start or goes out. Also, as air flow is dependent solely upon the chimney effect of the afterburner, fumes tend to escape from the kettle around the lid cover and other locations even when the afterburner is operational. Additionally, operation of afterburners is limited to roofing kettles and the like and generally is not applicable for use at other locations such as on the roof itself.
Thus, a need continues to exist for apparatus for recovering fumes from a roofing kettle or the like which overcomes the disadvantages and deficiencies of prior approaches at solving this problem.
The present invention solves this need and other problems in the field of fume recovery especially for the roofing industry by providing, in the preferred form, apparatus and methods for drawing air in fluid communication with the fumes of a container of heated material through a conduit and past a burner assembly in the conduit, with the flame of the burner burning or otherwise consuming the fumes of the container.
In most preferred aspects, the conduit is horizontally arranged and terminates in the hollow interior of a housing so that fresh air can also be drawn from the hollow interior in addition to the air drawn through the conduit, with fresh air also being provided to the burner assembly inside of the conduit.
It is thus an object of the present invention to provide novel methods and apparatus for recovering fumes.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus especially adapted for mobile applications between various job sites and especially in the roofing industry.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus having relatively low air flow rates while preventing the tendency of fumes to escape from the source during operation.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus having reduced capital costs.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus having reduced operational costs.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus which do not require disposal of collected material.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus having reduced operational noise.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus having reduced risk of igniting the fumes or the material source of the fumes.
It is further an object of the present invention to provide such novel fume recovery methods and apparatus of a minimal size which is easy to handle and transport.